‘What about her dad?’

‘Danny? We couldn’t tell Danny! She wanted to at first but I made her promise not to. I was just trying to limit the damage this was doing, to all of us. But look at us now … This is all my fault.’

‘Did Callie know who it was? Did she ever give you a name?’

‘No. That was why I didn’t think there was any point telling you everything. I didn’t want her getting into trouble. She was tricked, just like I told you lot, that’s still true. She thought she was talking to some boy at first, a boy her age who was being friendly. But she was being groomed. She sent off some photos, a silly little girl who just wanted a boy to like her. But it wasn’t a boy at all. If the others knew that she was the one who had shared the girls’ details, if they knew she had introduced him, that she was the start of it all, it would be the end for her. She would be hounded.’

Joel took a moment to try and organise his thoughts. ‘But the other girls must know, if she introduced them to someone who blackmailed them. How can you keep that secret?’

Sharon shifted now, finally struggling upright. Joel and DS Rose stayed seated as she paced to the door and for a moment Joel thought she was going to leave. Instead she stood facing it, gazing out of the slit of a window as she spoke again. ‘It’s not so simple. Whoever this man was, he’s clever. He uses a few social media accounts. In one of them he was posing as a teenage girl – that was the account that Callie pushed. She had no choice. She knew it wasn’t really a teenage girl by then but she still gave it her endorsement so the other girls linked with this account too. She had to. Then he would involve other accounts in their conversations … I don’t even think Callie was sure what was real and what wasn’t by the end.’

‘And he used one of those accounts to blackmail them?’